The use of at least one diazonium salt bearing an initiator function, for forming an undercoat obtained by grafting a graft derived from the diazonium salt and bearing an initiator function at the surface of a conductive or semiconductive material on the undercoat, and for forming on the undercoat a polymeric layer obtained by polymerization, in particular free radical polymerization, in situ of at least one monomer, initiated from the initiator function.

Claim:

The invention claimed is:

1. A diazonium salt corresponding to one of the following chemical formulae: ##STR00016##